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ABSTRACT: A comprehensive experimental/numerical procedure is formulated and validated for the in vivo characterization of the mechanical properties of human skin and the simulation of reconstructive surgery. The procedure uses in vivo experimental tests on undermined skin flaps, which can be performed during surgery, a numerical model formulated within the framework of nonlinear finite strain elasticity and a nonlinear parameter identification technique for the calibration of the model from indirect measurements. The procedure is applied to characterize the scalp skin tested in Raposio and Nordström (Skin Res. Technol. 4 (1998) 94). The skin is treated as a time independent, isotropic and hyperelastic membrane and the problem is solved through a finite element discretization. The study highlights that the model parameters can be determined with good accuracy using displacement measurements of a few points in the domain.
Journal of Biomechanics 12/2005; 38(11):2237-47. · 2.43 Impact Factor
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ABSTRACT: When isolating hair grafts in hair transplantation procedures, it is generally recommended to preserve the grafts at a low temperature (1 degrees C- 4 degrees C) in order to enhance the survival rate of the grafted hairs. This study was carried out to test the real benefits provided by cold-storing hair grafts.
The aim of this study was to evaluate, in an in vitro model, the effects of cooling micrografts during hair transplantation procedures to experimentally assess the soundness of this approach to enhance the survival and growth rates of hair micrografts.
A total of 240 anagen hair follicles were obtained from 10 healthy male patients. Follicles were thus randomly assigned to one of the following groups: group A (control; n = 120 follicles), or group B (experimental; n = 120 follicles). Follicles from group A were preserved for 5 hours at room temperature (26 degrees C), and follicles from group B were preserved for 5 hours at 1 degrees C. Immediately after that 5-hour period, follicles from both groups were then cultured for 10 days. The length of each follicle was measured immediately following the 5-hour test period and at the end of the 10-day culture period.
No statistically significant differences were found between the survival and growth rates of follicles from the control (survival rate = 87%, mean 10-day growth rate = 2.68 mm) and experimental (survival rate = 88%, mean 10-day growth rate = 2.54 mm) groups.
Although, at present, it is generally assumed that lowering the metabolism of grafts by reducing their temperature may be of some utility for enhancing their survival rate, our data indicate of that there are no effects when performing hair transplantation surgery.
Dermatologic Surgery 10/1999; 25(9):705-7. · 1.80 Impact Factor
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ABSTRACT: The aim of this study was to test the ex vivo biomechanical properties of acutely expanded scalp flaps to quantitatively assess the efficacy of acute scalp expansion. A total of 14 fresh male cadavers were used for the study. In each cadaver, a rectangular (4 x 10 cm), laterally based flap was designed on each side of the scalp, starting from the superior margin of the external auditory canal. One randomly selected flap per scalp underwent acute intermittent expansion (a 3-minute expansion/3-minute rest cycle was performed three times with the maximum expansion achievable); the contralateral flap served as a control. After the expansion process, the acutely expanded flaps were measured to assess whether applied biomechanical stress caused any changes in flap dimensions. The biomechanical properties (stress/strain ratio, mean stiffness) of both expanded and control flaps were then assessed by means of a dynamometer and a force transducer. The obtained data showed that the biomechanical benefits provided by acute scalp expansion were not statistically different (p < 0.05) from those obtained by simple subgaleal undermining. No change of length nor gain in compliance was observed in the acutely expanded flaps as compared with control scalp flaps. In the authors' opinion, a possible explanation (to be further validated) for the lack of effect of acute scalp expansion might be that the inelastic galea aponeurotica did not allow mechanical creep to exploit the inherent elastic properties of the overlying scalp skin.
Plastic & Reconstructive Surgery 05/1999; 103(6):1645-9. · 3.38 Impact Factor
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ABSTRACT: The aim of this article is to present two new techniques for digital flexor tendon repair: a modification to the conventional Kessler technique (wrap core suture) and tendon splints (H-shaped splint). These techniques were aimed at enhancing the biomechanical properties of such repairs as related to resistance to both gap formation and repair failure. Comparing (in an ex vivo study) the tensiometric properties (gap formation and failure strengths) of 24 flexor digitorum profundus tendons repaired with the described techniques (12 repairs per each technique) and the conventional Kessler repair (24 repairs), we found that the former provided significantly stronger repairs than the latter in vitro. A statistically significant difference (p < 0.001) was found between each of the two presented techniques and the Kessler repair. The wrap core suture increased the load at which a visible (1 mm) gap formed by 22.6 percent when compared with the conventional Kessler suture. The mean gap strength of the wrap core repair was 6.5 N, whereas that of the conventional Kessler was 5.3 N. The failure loads (ultimate strength) of the wrap core suture were 33.8 percent higher than those of the conventional Kessler. The mean breaking load of the wrap core repair was 19.4 N, whereas that of the conventional Kessler was 14.5 N. The H-splint repair increased the load at which a visible gap formed and the failure loads (ultimate strength) by 158.5 and 333.1 percent, respectively, when compared with the conventional Kessler suture. The mean gap strength of the H-splint repair was 13.7 N, and its mean breaking load was 62.8 N.
Plastic & Reconstructive Surgery 05/1999; 103(6):1691-5. · 3.38 Impact Factor
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ABSTRACT: Aims of this study were to evaluate whether it is possible to determine, by means of isoelectric focusing, an enzymic differentiation in human amniotic fluid, and whether the onset of fetal cleft lip and palate is accompanied by a pathologic enzymatic differentiation pattern in amniotic fluid. From January of 1993 to June of 1996, amniotic fluid samples from 315 healthy pregnant women (ages 22 to 43 years, mean 37 years; gestational age 14 to 22 weeks, mean 17 weeks) were examined. The normality of all pregnancies was confirmed at birth. Moreover, amniotic fluid samples were examined from three pregnancies (ages 36, 35, and 30 years; gestational ages 16, 18, 24 weeks) with fetal unilateral cleft lip and palate (confirmed at birth), diagnosed by ultrasound. The authors have tested as "metabolic" markers the enzymes lactate dehydrogenase and creatine phosphokinase. For the concentration rates of both the tested enzymes, a statistically significant difference (p = 0.003) was found between amniotic fluid samples obtained from normal and affected pregnancies. These data, in the authors' opinion, corroborate the hypothesis that a local metabolic impairment is somehow involved in the pathogenesis of cleft lip and palate.
Plastic & Reconstructive Surgery 03/1999; 103(2):391-4. · 3.38 Impact Factor
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ABSTRACT: When performing hair transplantation procedures, it is of the foremost importance to try to obtain the maximum survival rate possible of transplanted micrografts.
Aim of this study was to evaluate, in an in vitro model, the effects of preserving micrografts, for five hours, in an enriched storage medium in order to enhance the survival rate of hair micrografts.
A total of 200 human anagen hair follicles was obtained from ten male patients. Follicles were thus randomly assigned to one of the following group: Group A (control; n = 100 follicles), preserved for five hours in saline, and Group B (experimental; n = 100 follicles), preserved for five hours in a storage medium, containing adenosine triphosphate-magnesium chloride and deferoxamine mesylate. Isolated hair follicles from both Groups were then cultured for 10 days.
A statistically significant difference was found between the survival rate of experimental (98%) and control follicles (87%).
In our opinion, a "metabolic preconditioning" of micrografts by means of storing them for 5 hours in the described medium may be of some utility in augmenting the survival rate of hair grafts when performing hair transplantation surgery.
Dermatologic Surgery 01/1999; 24(12):1342-5; discussion 1346. · 1.80 Impact Factor
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ABSTRACT: This article describes an operative technique, based on the use of three anchoring galeal flaps, aimed at reducing the percentage of "stretch-back" that occurs after performing scalp reduction procedures. In 12 male patients undergoing a midline scalp reduction procedure, three rectangular (2 x 3 cm) galeal flaps in direct continuity with the longitudinal margin of the left scalp flap were sutured individually to the galeal undersurface of the right scalp flap to draw the two scalp flaps toward the midline of the scalp and to relieve the wound margins of closing tension. Tattoo marks were placed on the patient's scalp at the level of the vertical lines drawn through the external auditory meatuses (A1-A2) and 6 cm more posterior (B1-B2) to measure the movement and stretching of the scalp. The results were compared with those obtained from a control group of 13 male patients who underwent the same surgical procedure but without the use of the anchoring galeal flaps. Mean stretch-back (as measured 4 weeks postoperatively) at level A1-A2 was 8.3 mm in the control group and 1.6 mm in the experimental group. The mean stretch-back at level B1-B2 was 7.7 mm in the control group and 0.9 mm in the experimental group. A statistically significant difference (p < 0.005) was found between data from the control and experimental groups regarding the above-reported stretch-back values at both levels. The use of the described galeal flaps allowed us to obtain an 80.93-percent and an 88.09-percent stretch-back reduction at levels A1-A2 and B1-B2, respectively, 1 month postoperatively.
Plastic & Reconstructive Surgery 01/1999; 102(7):2454-8. · 3.38 Impact Factor
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ABSTRACT: Palmar and axillary hyperhidrosis are best treated surgically by endoscopic transthoracic upper dorsal sympathectomy. At present, this methodology relies on (at least) double trocar insertion (per side), carbon dioxide insufflation, or both. We present a new minimally invasive endoscopic transthoracic technique, performed by a single-entry specifically modified thoracoscope and without the need for carbon dioxide insufflation, with the aim to reduce the drawbacks associated with the above-mentioned, currently adopted endoscopic technique. In our opinion, this "single-entry" technique, compared with the other reported approaches, should theoretically minimize any damage to the intercostal neurovascular bundle, while avoiding the complications related to carbon dioxide insufflation.
Plastic & Reconstructive Surgery 11/1998; 102(5):1629-32. · 3.38 Impact Factor
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ABSTRACT: To better evaluate the role of a possible mitochondrial alteration in the pathogenesis of cleft lip, we obtained and examined 38 orbicularis oris muscle specimens taken from the cleft margin of both cleft and noncleft sides of 10 unilateral cleft lip infants at the time of primary closure. Part of each sample was frozen in liquid nitrogen/cooled isopentane, while the remainder was fixed in 2.5% glutaraldehyde, postfixed in osmium tetroxide, and embedded in Araldyte resin. Ten-micrometer-thick sections were obtained from the frozen samples and stained for histologic (Gomori trichrome) and histochemical (adenosine triphosphatase, nicotinamide adenine dinucleotide-tetrazolium reductase, cytochrome c-oxidase, succinate dehydrogenase) techniques. Ultra-thin sections (70 to 100 nm) of the resin-embedded specimens were stained with uranyl acetate and lead cytrate and were examined with a Zeiss 109 transmission electron microscope operating at 80 kV. Muscular fiber-type ratio was found to be 19.2 percent type 1 and 80.8 percent type 2 fibers on the cleft side and 26.3 percent type 1 and 73.7 percent type 2 fibers on the noncleft side. We detected aspecific structural alterations, such as variations in the fiber size without fiber group atrophy or fiber-type grouping with the ATPase reaction, in all biopsies. Although Gomori trichrome revealed a dark staining and red granularity of the fibers, suggesting an increase in mitochondria activity, no ragged-red fibers or cytochrome c-oxidase-negative/succinate dehydrogenase-positive fibers were found. At the ultrastructural level, the mitochondrial morphology was always preserved, without inclusions or variations in size and/or shape. On the other hand, we invariably noticed an increase of the number of mitochondria, associated with abnormal glycogen deposits, in some areas of every specimen. Both of these two latter findings were regularly localized at the periphery of the sarcolemma, resembling the so-called lobulated fibers, an aspecific sign of muscular flogosis. Our findings, although excluding an inherent metabolic myopathy of orbicularis oris muscle in unilateral cleft lip patients, evinced both an increased oxidative metabolism and a generic inflammatory condition of that muscle, the nature of which must still be defined.
Plastic & Reconstructive Surgery 10/1998; 102(4):968-71. · 3.38 Impact Factor
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ABSTRACT: A 62-year-old woman had a defect in the vertex of the scalp that was created by the excision of a basal cell carcinoma. This was closed with three local, hair-bearing, rhomboid flaps. This allowed us to reconstruct the natural whorl pattern of hair in this region.
Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery 10/1998; 32(3):339-41. · 0.94 Impact Factor
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ABSTRACT: The aim of the present study was to evaluate how much a relaxing incision of the galea aponeurotica affects the biomechanical properties of a scalp flap to quantify the surgery-related advantages provided by this procedure. Twenty scalp flaps, created by a reverse-Y incision down to and through the galea aponeurotica together with undermining (in the layer between the galea and the pericranium) to within 1 cm of the external auditory canal were studied. Data were collected by stepwise loading the scalp flaps before and after performing three full-thickness galeotomies lengthwise and parallel to the sagittal scalp incision. The tension/ extension ratio characteristics were computed, and loading curves as well as mean stiffness values were measured. A statistically significant difference (-16.6 g per millimeter) was found between the slope (computed as Young's modulus) of the curves obtained before and after performing the galeotomies. This value corresponded to a mean 40% reduction of the closing tension attained with each galeotomy. In the closing-tension interval 500 g to 1,500 g, the mean gain of length of the flap per galeotomy was 1.67 mm. These data confirm the usefulness of galeotomies for lengthening the scalp flaps and for diminishing the tension on wound margins when closing scalp defects.
Annals of Plastic Surgery 08/1998; 41(1):17-21. · 1.32 Impact Factor
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ABSTRACT: The aim of this study was to evaluate, in an in vitro model, the survival and growth rates of transversely sectioned human hair follicles to assess experimentally the soundness of this approach as a future possible method for "duplicating" available donor hair grafts in hair transplantation procedures. A total of 300 human anagen hair follicles was obtained from 10 healthy male patients. Follicles were thus randomly assigned to one of the following groups: group A (control; n = 100 follicles), cultured intact as dissected, and group B (experimental; n = 200 follicles), transversely transected, parallel to the epidermal surface and immediately below the bulge area, to obtain 200 lower-half follicles and 200 upper-half follicles. Isolated hair follicles from both groups were maintained in culture for 10 days. The length of each follicle was measured immediately following isolation and at the end of the 10-day culture period. No statistically significant differences were found between the growth rate of intact follicles (mean 10-day growth rate = 2.71 mm) and of lower-half follicles (mean 10-day growth-rate = 2.64 mm), whereas a statistically significant difference was found between the growth rate of follicles from the two above-mentioned groups and the growth rate of the "upper-half" follicles (mean 10-day growth rate = 1.07 mm). Histologic analysis demonstrated that both intact and lower-half follicles maintained a normal histologic appearance, whereas in upper-half follicle sections we invariably detected a region of intense cell proliferation, reminiscent of a regenerated follicular papilla, surrounding the lowermost part of the follicle. In our opinion, the reported in vitro survival rate of transected human hair follicles might represent an interesting starting point in striving to augment the number of donor hairs available during a hair transplantation procedure.
Plastic & Reconstructive Surgery 08/1998; 102(1):221-6. · 3.38 Impact Factor
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Plastic & Reconstructive Surgery 07/1998; 101(7):1931-3. · 3.38 Impact Factor
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ABSTRACT: Permanent expandable implants are widely used in breast reconstructive surgery, but their use in aesthetic surgery is still uncommon. Previous reports on breast expansion-augmentation using permanent expandable implants focused on immediate and early advantages but failed to evaluate long-term benefits, because the reservoir was removed a few months after implantation and the ability to adjust the implant size was lost. Since 1986, we have used permanent expandable implants in 129 women for unilateral or bilateral breast augmentation using the following approach: implants were positioned submuscularly through a transaxillary incision; the filling port was placed a few centimeters below the incision and permanently retained; the implants were positioned underinflated and then overexpanded starting 2 weeks after implantation; after a period of overinflation, deflation to the preoperatively planned volume was scheduled; patients' suggestions regarding final volume adjustments were followed; the effects of repeated overinflations and deflations were investigated in several different conditions. Permanent expandable implants offer unique long-term technical and psychological advantages in the management of highly demanding patients and in the following clinical situations: pregnancy, impending capsular contracture, contralateral progressive ptosis, tubular breasts(s), difficult mammographic examination, spontaneous deflation, and rippling. Disadvantages include economical cost, port-related problems, and repeated requests by patients for volume changes. Saline permanent expandable implants allowed less flexibility in adjusting the breast size and caused discomfort when overexpanded. Permanent expandable implants in breast aesthetic surgery offer several advantages, and because patients can play an active role in deciding volume adjustments, compliance is very high.
Plastic & Reconstructive Surgery 07/1998; 101(7):1964-72. · 3.38 Impact Factor
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ABSTRACT: In light of the recently described experimental technique of in vivo bone reconstitution with biotechnologic methods (from bone marrow stromal cells) and the prefabrication flap procedures, the possibility to obtain autologous bone growth in a myocutaneous flap, thus creating a composite osteomyocutaneous preformed flap, is postulated. Human bone marrow stromal cells were delivered into the latissimus dorsi of athymic mice by a porous hydroxyapatite ceramic model. Eight weeks after the implantation, histologic examination revealed the presence of spongious bone tissue. A simple myocutaneous flap was thus transformed into a composite osteomyocutaneous flap. This flap is called the biotechnologic prefabricated flap, because it was the result of ex vivo expanded osteogenic precursor cells and in vivo bone tissue neoformation. The shape of the bone flap was exactly the same as the shape of the ceramic model used. A possible clinical application may be the correction of skeletal defects. The advantages of this procedure are simple surgical execution, the possibility of preshaping the graft to the exact characteristics of the defect, and the availability of autogenous donor tissue without donor site morbidity.
Plastic & Reconstructive Surgery 04/1998; 101(3):577-81. · 3.38 Impact Factor
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ABSTRACT: The aim of this paper is to introduce a computer program developed to provide objective, quantitative data useful to ensure proper expander selection when having to use a rectangular tissue expander. The program is developed to calculate the volume of a rectangular tissue expander to obtain the exact amount of yield needed to allow for reconstruction of a determined defect. The only data to be supplied are the length and the width of the defect to be reconstructed. In our opinion, although its use is not aimed at replacing clinical judgment based on experience and careful observation, this program may be considered a simple and useful adjunct for the inexperienced surgeon (or the occasional operator) planning to use a rectangular tissue expander.
Annals of Plastic Surgery 11/1997; 39(4):416-7. · 1.32 Impact Factor
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ABSTRACT: We report a woman who underwent augmentation mammaplasty as part of a clinical trial of the Trilucent (soybean oil-filled) breast implant in Genoa, Italy. Five months after surgery a mammography was performed in response to the patient's complaints of pressure and tightness in the area of her left breast. The mammogram clearly demonstrated a 5-mm fibroadenoma of the left breast. This is the first documented case of a nonpalpable breast lesion that was detected by mammography through the new radiolucent, triglyceride-filled implant.
Annals of Plastic Surgery 11/1997; 39(4):333-6. · 1.32 Impact Factor
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ABSTRACT: Starting from MR and CT images for a given patient, a new single image representation of all parameters has been generated by using false-color techniques in a standard UNIX and X-11 environment. A transformation linking together the MR, CT parameters and the RGB (red, green, blue) color components has been used. Moreover an unsupervised segmentation method based on a number of neural and fuzzy models may directly produce segmented image volumes. Each image of the various sequences has been interactively displayed by using a specifically designed application. The resulting images have been displayed on a stereo monitor allowing the three-dimensional rendering of visual data through LCD shuttered glasses. Moreover, a 3-D control system based on low frequency magnetic fields has been used, while a bandheld Polhemus stylus could be used as an electronic knife for dissecting the 3-D data set and for defining flaps and grafts. Bone or soft-tissue contour can be analyzed, and sections can be removed from the model to allow a view of the underlying structures. Flaps and grafts obtained utilizing the above-reported techniques can be fitted exactly, without repeated removal and recarving. Nuances of depth, tapering, and arc are carved directly into the bone, while chances of asymmetry are markedly diminished. In this way, moreover, anesthetic times are reduced by more efficient utilization of operative time, which usually offsets the increased cost of imaging.
Studies in health technology and informatics 02/1997; 39:232-6.
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ABSTRACT: Total 3-D reconstruction of the tumor size, shape, and relations with surrounding structures using CT, MRI, sonography, and angiography images can make simulated radical resection of soft-tissue sarcomas possible, thus sparing normal tissues. With our approach, starting from three MR images for a given patient, a new single image representation of all three parameters is generated by using two different techniques on a workstation in a standard UNIX and X-11 environment. The first one is a transformation linking together the MR parameters and the RGB (red, green, blue) color components. The second one is an unsupervised segmentation method based on a number of neural and fuzzy models. We can dinamically render and update a stereo display using field sequential presentation of left and right eye views on the monitor, with Cristal Eyes LCD shutter eyewear (StereoGraphics Inc., San Rafael, CA) to view it. As 3D locating tool, a 3D locating control system based on low-frequency magnetic fields (Polhemus Fastrak) has been chosen. Simulations of soft-tissues excisions may be performed in this interactive environment with augmented-reality modalities. All this, in our experience, has greatly facilitated the simulation of soft-tissue sarcoma excisions.
Studies in health technology and informatics 02/1997; 39:125-30.
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ABSTRACT: Ten patients with primary or recurrent cancer of the chest wall underwent full-thickness resection and immediate reconstruction of the defect by placement of an alloplastic implant and transposition of a latissimus dorsi (n = 5) or transverse rectus abdominis (n = 5) myocutaneous flap. When up to three ribs were removed, these were replaced by a reabsorbable mesh sutured to the residual rib stumps. Larger skeletal defects were stabilized by placement of a permanent mesh or polytetrafluoroethylene (PTFE) sheet. In only one case the PTFE reconstruction was reinforced by metallic implants, but that caused dehiscence of the overlying flap suture, leading to major complications and eventually death. Both the latissimus dorsi and the rectus abdominis myocutaneous flaps were ideally suited to soft tissue reconstruction. There were no appreciable complications concerning viability of the flaps, and the operating time needed for the transposition of the two flaps was similar. The rectus abdominis flap showed a distinct advantage when an absorbable mesh was to be covered, as its superior thickness minimized the risk of creating a 'flail' reconstructed chest wall. This advantage was in part counter-balanced by the more limited arc of rotation compared with the latissimus dorsi flap.
Scandinavian Journal of Plastic and Reconstructive Surgery and Hand Surgery 04/1995; 29(1):39-43. · 0.94 Impact Factor
